Hydraulically operated tool



April 1957 c. v. CHESTER-BROWNE ETAL 3,314,488

HYDRAULI CALLY OPERATED TOOL 5 Sheets-Sheet 1 Filed May 15, 1964 HYDRAULICALLY OPERATED TOOL Filed May 15, 1964 3 Sheets-Sheet 2 N GE April 1967 c. v. CHESTER-BROWNE ETAL 3,314,488

HYDRAULICALLY OPERATED TOOL I Filed May 15, 1964 3 Sheets-Sheet s United States Patent 3,314,488 HYDRAULICALLY OPERATED TOOL Christopher Val Chester-Browne, Soherton, Southampton,

and Edward Addison and David McCandlish, Weymouth, Dorset, England, assignors to Vickers-Armstrongs (Engineers) Limited, London, England, a British company Filed May 13, 1964, Ser. No. 367,066 Claims priority, application Great Britain, May 23, 1963, 20,595/63; Oct. 31, 1963, 43,113/63 15 Claims. (Cl. 173-127) This inVentiOn is concerned with a hydraulically operated tool.

According to the present invention there is provided a hydraulically operated tool comprising a body, a piston and cylinder actuator carried by the body, an element connected to the actuator for imparting, when the piston reciprocates in the cylinder, motion to a tool head for engaging the work on which the tool is to operate, means for attaching the tool head to the body so that the head is capable of limited movement relative to the body, and an inlet for connection to a source of liquid under pressure, there being valve means for connecting the cylinder bore to the inlet in such a way that the piston is caused to reciprocate in the cylinder.

Said element may be arranged for striking the tool head in use of the tool, or said element may be rigidly connected to the tool head as, for example, in cases where the invention is applied to tamping apparatus or concrete vibrators.

For a better understanding of the present invention and to show how the same may be carried into effect, reference will now be made, by way of example, to the accompanying drawings, in which:

FIGURE 1 is a partly sectioned side view of a hydraulic rock drill,

FIGURE 2 is a longitudinal sectional detailed view of a portion of the rock drill shown in FIGURE 1,

FIGURE 3 is a longitudinal sectional view of a sleeve of a valve-employed in the rock drill of FIGURE 1,

FIGURE 4 is a section on either of the lines VIII-VIII of FIGURE 3,

FIGURE 5 is a section on either of the lines IX-IX of FIGURE 3,

FIGURE 6 is a longitudinal sectional view of a control block for the drill of FIGURE 1,

FIGURE 7 is another longitudinal sectional view of the control block of the drill, the section being taken on a plane that is ditferent from the plane on which the section of FIGURE 6 is taken, and

FIGURE 8 is a view similar to FIGURE 3 showing a modified form of sleeve.

The drill of FIGURE 1 has a cylindrical casing 101 to one end of which a control block 102 having handles 103 is attached. The other end of the casing 141 is closed by an annular plate 104 carrying a tubular projection 105. Gussets 106 are secured to the projection 105 and the plate 104 forstrengthening purposes. A pick head retaining link 107 is mounted on the gussets 106 for loosely attaching a pick head 108 to the drill with an end portion of the pick head 108 passed through the projection 105. The pick head is in the form of a hexagonal bar which is pointed at its work-engaging end (not shown) and fiat at its opposite end 108A. A collar 109 is formed on the pick head 108, this collar being disposed between the free end of the projection 105 and the link 107. The free end of the projection 105 and the link 107 form stops that co-operate with the collar 109 to limit axial movement of the pick head 108 relative to the drill; The link 107 is in the form of a loop 107A pivotally attached by a pin 107B to one of the gussets 106. The loop has an opening that is wider adjacent the pin 3,314,488 Patented Apr. 18,1967

107B than it is remote from the pin. The collar 109 can pass through the wider part of the loop but not the narrower part. A spring-loaded catch 107C is carried on another of the gussets 106. With the catch 107C and link 107 in the position shown in full lines in the drawing the catch 107C prevents the link 107 from swinging to the position where the collar 109 can pass through the opening in the loop 107A. The collar 109 can only pass through the loop 107A when the link 107 is in the posi tion shown in chain dotted lines in the drawing.

A valve which is an improved form of valve is disposed in the casing 101. The valve (FIG. 2) has a valve body '110 secured in the bore of the casing 101 adjacent the control block 102. A sleeve 111 is fixed in the bore of the body and has a rotatable sleeve 112 mounted therein. A wide annular groove 113 is formed in the central part of the bore of the body 110 and narrower grooves 114, 115 are formed in the bore on either side of the groove 113. The sleeve 111 has four sets of ports therethrough, there being four ports 116 (FIG- URE 3) in the first set, four ports 117 in the second set, four ports 118 in the third set and four ports 119 in the fourth set. The axes of the ports in each set lie in the same plane and are spaced around the axis of the sleeve 111 at equiangular intervals. The ports 117 are longitudinally aligned with the ports 119 and the ports 116 are longitudinally aligned with the ports 118. The ports 116 and 118 are angularly spaced about the axis of the sleeve 1 11 by 45 from the ports 117 and 119. The plane of the longitudinal section-a1 view of FIGURE 3 is taken at 45 about the axis of the sleeve 111 from the plane of the section of FIGURE 1. The rotatable sleeve 112 has in the outer surface thereof a first set of four longitudinal grooves 120 and a second set of four longitudinal grooves 121. The grooves of each set are spaced at eq-uiangular intervals around the longitudinal axis of the sleeve 11-2. Those ends of the grooves 120 that are most remote from the grooves121 have ports 11-2 cooperating therewith to place the grooves 120 in communication with the interior of the sleeve 112. Similarly the grooves 121 at their ends most remote from the grooves 120 have ports 123 co-operating therewith and which place these grooves in communication with the interior of the sleeve 121. A ram piston 124 is disposed in the sleeve 112, the piston being carried on a piston rod 125. The portion 125A of the rod 125 that is to the left (FIGURE 2) of the piston 124 is of larger diam eter than the portion 125B of the rod 125. The free end of the portion 125A is entered in a stuffing box 126 which is fixed in the block 102, whilst the portion 125B passes through a stuffing box 127 secured to the valve body 110. Thrust bearings 128 are provided between the stutfing boxes 126 and 127 and the adjacent ends of the rotary sleeve 112. An extension 112A of the left-hand end (FIGURE 2) of the sleeve 112 has a gear wheel 129 of a gear-type oil motor 130 secured thereto by a key 131. The gear wheel 129 meshes with pinions 132 only one of which can be seen in FIGURE 6. Each pinion 132 is mounted on a pin 133 through the intermediary of a shell bearing 134, the pins being carried on the valve body 110. The side faces of the wheels 129 and 132 co-operate on one side with the end face 110A I of the valve body 110 and on the opposite faces with an end face 102A (FIGURE 6) of the block 102. The wheels 129 and 132 are disposed within a gear motor plate 130A.

The free end of the portion 125B of the piston rod 125 has a mass 135 secured thereon, the mass 135 having a face 135A for encountering the end 108A of the pick head 108. A collar 136 is secured on the mass 135. The collar 136 has holes 137 therethrough, there being tubes 138 passed with clearance one through each of the holes 137. In FIGURE 1 only one hole 137 and one tube 138 is visible. One end of each tube 138 is fixed to a stud 139 projecting from and secured to the valve body 110. Each stud 139 has a bush 140 threadedly mounted thereon. A coil spring 141 is provided in association with each tube 138, one end of the spring abutting against the collar 136 and the opposite end abutting against the associated bush 140. The opposite end of each tube 138 is secured to a tubular member 142 that is fixed to the plate 104 by a bolt 143. The tubular members 142 are passed through holes in the peripheral part of an annular plate 144. A spring 145 in the form of a pile of dished spring discs 146 is carried on each tubular member 142, between the plates 104 and 144. The springs 145 serve to urge the plate 144 against the shoulders 142A on the tubular members 142.

FIGURES 6 and 7 are sections of the control block 102 taken from the opposite side of the tool as compared with the view of FIGURE 1. The face 102A in each of FIGURES 6 and 7 is therefore on the left whereas in FIGURE 1 it is on the right of the block 102. The block 102 has an inlet passageway 147 for connection to a high pressure oil supply line (not shown). The passageway 147 (FIGURE 6) leads via. a spool valve 148, ports (not shown) and an oil filter 149 (FIGURE 7) to a passageway 150 that communicates via passages (not shown) with the groove 113 (FIGURE 2). The groove 113 communicates via passages (not shown), a passageway 151 and a throttle valve 152 with a passageway 153 that leads to supply pockets of the gear-type oil motor 130. The exhaust pockets of the motor 130 and the grooves 114 and 115 communicate via passages (not shown) with a passageway 154 (FIGURE 6) that leads to an outlet 155 which is adapted for connection to an exhaust line. The passageway 151 applies oil at the same pressure as that within the groove 113 to the piston 156 of an accumulator 157. The piston 156 is mounted on a rod 158 carrying a spring 159 in the form of a pile of dished spring discs 160 which are disposed in a cylindrical chamber 161 that is coaxial with and of a greater diameter than the cylindrical recess 162 that houses the piston 156. One end of the spring 160 abuts against a plug 163 secured in the block 102 whilst the other end of the spring urges the piston 156 into the recess 162. A helical groove 164 is formed on the cylindrical surface of the piston 156 and extends from one end of the piston to the other. The chamber 161 communicates via porting (not shown) with the passageway 154.

The spool valve 148 is opened by pressing a plunger 165 which is secured on one end of the spool valve 148 into the block 102 against the action of a spring 166 which bears on the other end of the spool valve 148 to urge the valve to its closed position. A lever 167, having a pad 167A for cooperating with the plunger 165, is pivotally mounted on the block 102 (see FIGURE 1) and serves when in the position shown in FIGURE 2 for maintaining the plunger 165 in the position where the valve 148 is open.

With the outlet 155 connected to an exhaust line and the inlet 147 connected to a high pressure oil supply line, the drill described above operates as follows. Upon depression of the plunger 165 into the block 102 high pressure oil is supplied to the annular groove 113. From the groove 113 the oil flows via the passageway 151, the throttle valve 152 and the passageway 153 to the oil motor 130 to drive the latter so that the gear wheels 129 and 132 rotate. Since the sleeve 112 is fixed to wheel 129 the sleeve rotates about the longitudinal axis of the drill. With the parts in the position shown in FIGURE 2 oil under pressure is supplied from the groove 113 via the ports 117 to the groove 120. The oil flows from the grooves 120 through the ports 122 to the annular space 168 that exists between the bore of the sleeve 112 and the piston rod portion 125A. Oil flows from the space 169 that is between the piston rod portion 125B and the bore of the sleeve 112 through the ports 123 to the slots 121 and from these slots via the ports 119 to the annular groove which leads to the passageway 154 and the outlet 155. The oil in the space 169 is thus connected to exhaust while oil under pressure is fed to the space 168. The piston 124 therefore moves the mass 135 to the right (FIGURE 2) to encounter the adjacent end 108A of the pick head 108 and impart a blow thereto. When the motor has turned the sleeve 112 through one-eighth of a revolution the grooves 120 place the space 168 in communication via the ports 116 (which cannot be seen in FIGURE 2) with the groove 114 that communicates with the outlet 155. At the same time the grooves 121 place the space 169 in communication via ports 119 (which cannot be seen in FIGURE 2) with the groove 113. Thus oil under pressure is fed to the space 169 and the space 168 is connected to exhaust. The piston 124 therefore moves the mass away from the pick 108 and in so doing compresses the springs 141. Upon a further eighth of a revolution of the sleeve 112 it will be understood that the mass 135 is again driven to encounter the pick 108 and upon a further eighth of a revolution the mass 135 is displaced in the opposite direction. Thus with continued rotation of the sleeve 112 the mass 135 is caused to oscillate and impart a series of blows to the pick 108. It will be appreciated that the springs 141 act to sore energy when the mass 135 moves away from the pick 108, this energy being subsequently released as the springs extend on the working stroke of the mass 135 to encounter the pick 108. It will be noted that the piston area on which the hydraulic fluid acts is greater on the right-hand side of the piston 124 than on its left-hand side (FIGURE 2). The holes 116 and 118 are of larger diameter than the holes 117 and 119. The slots 120 and 121 are all of the same circumferential width. It will be appreciated therefore that the valve constituted by the sleeves 111 and 112 is open when the piston is moving from right to left (FIGURE 2) for a greater part of the cycle than it is when the piston is moving in the opposite direction. The movement of the piston 124 in this latter direction is, however, faster than its movement from right to left because of the action of the springs 141.

The frequency of the blows imparted to the pick head 108 can be varied by altering the speed of rotation of the sleeve 112. This is effected by adjusting the throttle valve 152 thereby to change the speed of the motor 130.

The accumulator 157 is provided to minimise pressure fluctuations in the high pressure supply line. The groove 164 on the cylindrical surface of the accumulator piston 162 places the high pressure side in communication with the chamber 161 which is connected to the outlet 155. A rise in pressure in the passageway 151 is absorbed by displacement of the piston 156 against the spring 159 and by increased leakage along the groove 164 resulting from reduction of the effective length of this groove as the accumulator piston 156 moves into the chamber 161. i as! The springs (FIGURE 1) serves as buffers for absorbing energy of the mass 135 in the event of over-run of this mass occurring if the pick head 108 is not in contact with solid material. The mass 135 carries rubber pads 135B that can encounter the valve body 110 and stufling box 127 in the event of over-run of the mass 135 in the opposite direction.

FIGURE 8 shows a modification that may be made to the ports 117 and 119. In this figure these ports are of isosceles triangle form with the bases of the triangles parallel to the axis of the sleeve 111 and the apices of the triangles pointing against the direction of rotation of the sleeve 112. Thus as the sleeve 112 rotates the apices of the ports 117 and 119 are uncovered first and oil flows through these ports on the working stroke of the drill at a rate more nearly proportional to the speed of the piston 124 and mass 135 than when circular ports 117 and 119 are employed.

We claim:

1. A hydraulically operated tool comprising a body, a ported cylinder rotatably carried in the body and maintained against axial movement with respect to the body, a piston slidably entered in the cylinder, a tool head for engaging the work on which the tool is to operate, means attaching the tool head to the body to permit limited movement of the tool head relative to the body, an element connected to the piston for imparting, upon reciprocation of the piston in the cylinder, motion to said tool head, an inlet for connection to a source of liquid under pressure, and motor means for continuously rotating said cylinder, the body being formed with ducting leading from said inlet to co-operate with the porting in said cylinder which, upon rotation, controls admission and exhaust of liquid to and from said cylinder to reciprocate said piston within the cylinder.

2. A tool according to claim 1, and further comprising spring means urging said piston towards the tool head attaching means, wherein the piston is double acting with a larger working surface area for the return stroke, in which the piston moves against the action of the spring means, than working surface area for the forward stroke, in which the spring means assists the piston.

3. A tool according to claim 1, and further comprising means for cushioning excessive movement of said element in a direction towards said tool head attaching means.

4. A tool according to claim 1, and further comprising means for cushioning excessive movement of said element in a direction away from said tool head attaching means.

5. A tool according to claim 1, and further comprising a hand-operable spring-biased spool valve for regulating flow from said inlet.

6. A tool according to claim 1, and further comprising an accumulator connected to said inlet for minimising pressure variations in the supply to said inlet.

7. A tool according to claim 1, wherein said element is a striking element for imparting repeated blows to said tool head in use of the tool.

8. A tool according to claim 1, wherein said rotating means is hydraulically driven, there being a supply line for hydraulic fluid for said rotating means leading from said inlet.

9. A tool according to claim 8, wherein said rotating means is a gear type oil motor, a gear of the motor being fixed to said cylinder and a pinion of said motor being rotatably mounted on said body.

10. A tool according to claim 1, wherein the cylinder is formed with porting to make the piston and cylinder assembly double acting, liquid from said inlet being admitted alternately to opposite end faces of said piston, there being fluid outlet ducting co-operating with the porting of said cylinder permitting escape of liquid from the decreasing volume part of said cylinder bore.

11. A hydraulically operated tool comprising a body, a ported cylinder rotatably carried in the body and maintained against axial movement with respect to the body, a piston slidably entered in the cylinder, a tool head for engaging the work on which the tool is to operate, means attaching the tool head to the body to permit limited movement of the tool head relative to the body, an element connected to the piston for imparting, upon reciprocation of the piston in the cylinder, motion to said tool head, an inlet for connection to a source of liquid under pressure, and means for rotating said cylinder, the body being formed with ducting leading from said inlet to co-operate with the porting in said cylinder which, upon rotation, controls admission and exhaust of liquid to and from said cylinder to reciprocate said piston within the cylinder,

the cylinder being provided with porting to make the piston and cylinder assembly double acting so that liquid from said inlet is admitted alternately to opposite end faces of said piston, fluid outlet ducting co-operating with the porting of said cylinder permitting escape of liquid from the decreasing volume part of said cylinder, said body of the tool including a sleeve receiving said cylinder rotatably therein, the remainder of said body being provided with grooves open to the outer surface of the sleeve and the sleeve being provided with holes communicating with said grooves for co-operating with the porting in said cylinder, said grooves and holes forming part of said ducting.

12. A tool according to claim 11, wherein the cylinder is formed with two sets of longitudinally extending grooves in the outer surface thereof, one said set being associated with one of the chambers into which the cylinder bore is divided by the piston and the other said set being associated with the other chamber of the cylinder, the cylinder having ports placing each groove in communication with its associated chamber, lands on the outer surface of the cylinder between the grooves of each set opening and closing said holes upon rotation of the cylinder thereby controlling the fiow of liquid into and out of said chambers.

13. A tool according to claim 12, wherein the grooves in said remainder of the body are annular, there being a central groove in communication with said inlet and two end grooves in communication with exhaust, and wherein there are four sets of said holes, one set for each end groove and two further sets for the central groove, one of said further sets being associated with one said chamber and the other of said further set being associated with the other chamber, the holes of said one further set each being longitudinally aligned and forming first pairs with corresponding holes of the end groove set associated with said other chamber and the holes of said other further set each being longitudinally aligned and forming second pairs with corresponding holes of the end groove set associated with said one chamber, the holes of each set being equally spaced around the sleeve with said first pairs of aligned holes circumferentially midway between adjacent second pairs of aligned holes, there being as many grooves in each set of grooves as there are holes in each set of holes, and the grooves of the sets Otf grooves being longitudinally aligned and equally spaced around the cylinder.

14. A tool according to claim 13, wherein piston rods project from both end faces of the piston, the rod projecting from the end of the piston adjacent the tool attaching means being of lesser diameter than the rod at the other end of the piston, and wherein the holes associated with the annular end groove remote from the tool attaching means and the holes aligned therewith are larger than the other holes.

15. A tool according to claim 14, wherein said other holes are of isosceles triangle shape, their apices pointing against the intended direction of rotation of the cylinder.

References Cited by the Examiner UNITED STATES PATENTS 784,703 3/ 1905 Potter 91-315 912,234 2/1909 Doughty 173-134 1,419,269 6/1922 Keller 173137 1,784,012 12/1930 Towett 173--137 2,851,010 9/1958 Mori 173-1 19 3,204,534 9/ 1965 Spannkake 9140 FOREIGN PATENTS 298,935 10/ 1928 Great Britain.

FRED C. MATTERN, JR., Primary Examiner. L. P. KESSLER, Assistant Examiner. 

1. A HYDRAULICALLY OPERATED TOOL COMPRISING A BODY, A PORTED CYLINDER ROTATABLY CARRIED IN THE BODY AND MAINTAINED AGAINST AXIAL MOVEMENT WITH RESPECT TO THE BODY, A PISTON SLIDABLY ENTERED IN THE CYLINDER, A TOOL HEAD FOR ENGAGING THE WORK ON WHICH THE TOOL IS TO OPERATE, MEANS ATTACHING THE TOOL HEAD TO THE BODY TO PERMIT LIMITED MOVEMENT OF THE TOOL HEAD RELATIVE TO THE BODY, AN ELEMENT CONNECTED TO THE PISTON FOR IMPARTING, UPON RECIPROCATION OF THE PISTON IN THE CYLINDER, MOTION TO SAID TOOL HEAD, AN INLET FOR CONNECTION TO A SOURCE OF LIQUID UNDER PRESSURE, AND MOTOR MEANS FOR CONTINUOUSLY ROTATING SAID CYLINDER, THE BODY BEING FORMED WITH DUCTING LEADING FROM SAID INLET TO CO-OPERATE WITH THE PORTING IN SAID CYLINDER WHICH, UPON ROTATION, CONTROLS ADMISSION AND EXHAUST OF LIQUID TO AND FROM SAID CYLINDER TO RECIPROCATE SAID PISTON WITHIN THE CYLINDER. 